PURPOSE: to measure the electric activity of the masseter and temporal muscles, to verify the graduation of the pain to palpation and its correlation with the electric activity in subjects with bruxism. METHOD: all subjects were examined according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) instrument combined with the dentistry and the speech pathology evaluation. The electric activity in the masticatory muscles was measured based on surface electromyography in the following situations: during rest, maximum intercuspation and during usual mastication rhythmic. In the collection and analysis of the electromyography signals, it was used BioInspector®, 1.8 (Lynx®), and AqDAnalysis®, 7.0 (Lynx®), and the data were quantified on RMS (root mean square) and expressed in µV (microvolts). The statistic analysis was based on the Spearman Coefficient with 5% significance level. RESULTS: the results showed that EMG pattern of the studied muscles was found next to the levels to normality in the rest, maximum intercuspidation and in the rhythmic habitual mastication. Most of the subjects with bruxism had a complaint of some pain, being more evidenced the severe degree and mainly in the masseter muscle. There was not evidenced statistically significant correlation between pain and activity EMG, once that this last one was next to the normality levels. CONCLUSION: the analysis of the results indicated that in spite of the presence of pain in the masticatory muscles, most of the correlations between pain and EMG were weak and without statistical significance, indicating that pain did not intervene with the performance of the electric activity of the studied muscles in the evaluated situations.
Bruxism; Electromyography; Masticatory Muscles; Facial Pain
